The LRRK2 (Leucine-Rich Repeat Kinase 2) gene encodes a large multi-domain protein with kinase activity. Pathogenic variants in LRRK2 are among the most common genetic causes of familial Parkinson's disease.
| Property | Value |
|----------|-------|
| Gene Symbol | LRRK2 |
| Full Name | Leucine-Rich Repeat Kinase 2 |
| Chromosomal Location | 12q12 |
| NCBI Gene ID | 120892 |
| OMIM | 609007 |
| Ensembl ID | ENSG00000188906 |
| UniProt ID | Q5S007 |
| Inheritance | Autosomal Dominant |
| Protein Domains | ROC (Ras of complex), COR, Kinase, LRR, ANK, WD40 |
LRRK2 is a large cytosolic protein (2527 amino acids) with multiple functional domains:
- Kinase domain: Phosphorylates target proteins (including itself through autophosphorylation)
- ROC domain: GTPase activity, regulates protein interactions
- COR domain: Mediates dimerization
- LRR domain: Protein-protein interactions
- WD40 repeat: Scaffold for protein complexes
- Neuronal signaling: Regulates various signaling pathways in neurons
- Protein sorting: Controls vesicular trafficking through Rab GTPase interactions
- Mitochondrial function: Associates with mitochondrial outer membrane
- Synaptic plasticity: Involved in dopamine receptor signaling
- Autophagy regulation: Modulates autophagic processes
Parkinson's Disease (PD) - LRRK2 is the most common genetic cause of late-onset familial PD, accounting for 5-10% of familial cases and 1-5% of sporadic cases.
| Mutation |
Domain |
Effect |
Prevalence |
| G2019S |
Kinase |
Increased kinase activity |
Most common (~5% familial PD) |
| R1441C |
ROC |
Impaired GTPase activity |
Second most common |
| R1441G |
ROC |
Impaired GTPase activity |
Common in Basque population |
| R1441H |
ROC |
Impaired GTPase activity |
Variable penetrance |
| Y1699C |
COR |
Altered function |
Rare |
| G2385R |
WD40 |
Risk variant |
Asian populations |
| R1628P |
WD40 |
Risk variant |
Asian populations |
- G2019S: Common in European and North African populations (up to 30% of familial PD in some populations)
- R1441G: Highly prevalent in Basque population (up to 50% of familial PD)
- G2385R: Risk factor in East Asian populations
The penetrance of LRRK2 mutations is age-dependent and incomplete:
- G2019S: ~70% by age 80
- R1441C/G: ~30-50% by age 80
- Variable depending on specific mutation and population
- Kinase hyperactivity: G2019S increases kinase activity, leading to enhanced downstream signaling
- GTPase dysfunction: R1441 mutations impair ROC domain function
- Mitochondrial dysfunction: Altered mitochondrial quality control
- Dysregulated autophagy: Impaired lysosomal and autophagic clearance
- Neuroinflammation: Activation of microglia and inflammatory pathways
LRRK2 is widely expressed in the central and peripheral nervous system:
- Substantia nigra - Dopaminergic neurons (vulnerable in PD)
- Cortex - Especially frontal and temporal regions
- Striatum - Major target of dopaminergic input
- Hippocampus - Involved in learning and memory
- Peripheral tissues - Kidneys, lungs, immune cells
Expression is also prominent in:
- Kidney and lung tissue
- Immune cells (monocytes, macrophages)
- LRRK2 kinase inhibitors: Small molecule inhibitors (e.g., DNL151, BIIB122)
- Antisense oligonucleotides: siRNA approaches to reduce LRRK2 expression
- Protein-protein interaction inhibitors: Targeting ROC-COR or LRR domain interactions
- Multiple LRRK2 kinase inhibitors in clinical trials for PD
- Immunotherapy approaches targeting LRRK2-associated pathology
- Personalized medicine: Targeting LRRK2-positive PD patients
- Biomarker development: LRRK2 activity as a disease biomarker
- Neuroprotection: Strategies to prevent dopaminergic neuron loss
- Modulating protein clearance: Enhancing autophagy to clear mutant protein
- Paisán-Ruíz et al., Cloning of the gene containing mutations that cause PARK8-linked Parkinson's disease (2005)
- Zimprich et al., Mutations in LRRK2 cause autosomal-dominant parkinsonism with pleomorphic pathology (2004)
- Di Fonzo et al., A common missense variant in LRRK2 is a major risk factor for Parkinson's disease (2005)
- Cookson, The role of leucine-rich repeat kinase 2 (LRRK2) in Parkinson's disease (2010)
This section highlights recent publications relevant to this disease.